Max buy-sell profit problems.
Given a one-dimensional array of stock prices, what is the maximum profit that could have been achieved given a specific number of transactions?
You can only buy/sell one share at a time. You must alternate buying and selling (i.e. you can't hold shares)
e.g.
Given [1, 2, 3, 4, 5, 1, 3] as a stream of prices, with 4 transactions, the best profit you could make is 6 - buy on day 0, sell day 4, buy day 5, sell day 6.